private void addButton_Click(object sender, EventArgs e) { Customer customer = new Customer(); customer.Name = nameTextBox.Text; //Name unique check if (_customerManager.IsNameExists(customer)) { MessageBox.Show(nameTextBox.Text + " Already Exists!"); return; } customer.address = addressTextBox.Text; customer.contact = contactTextBox.Text; if (_customerManager.AddMethod(customer)) { MessageBox.Show("Saved"); } else { MessageBox.Show("Not saved"); } showDataGridView.DataSource = _customerManager.ShowMethod(); }